This invention relates to food products, and more particularly, to potato chips.
Snack foods have become a part of the diet of many persons. Some of the more popular snack foods contain undesirably high levels of ingredients introduced during the preparation process, one of the more important being high levels of fat. Although certain amounts of fat are necessary in the diet of most persons, deep-fat-fried snack foods may contain as much as 50% by weight of fat, which is soaked into the food product during the deep-fat frying. Such high levels of fat consumed in the snack food can lead to a fat imbalance in the body, which in turn can have adverse health effects, and the fat also adds to the calorie content of the snack food.
One of the more popular snack foods for many years has been potato chips. Conventional potato chips are prepared by placing raw or blanched potato slices into deep-fat or oil cookers, with the deep-fat or oil frying resulting in a reduction of moisture content to less than 5%, but also resulting in an undesirable increase in the oil or fat content to the range of about 30-50% of the total weight of the chip. This high fat content is undesirable in the diet when potato chips are consumed in large quantities, and the high fat content also leads to shortened shelf life of the potato chip due to the infused fat becoming rancid over a period of time. Further, deep-fat frying is inherently a difficult and expensive manufacturing operation, due to the cost of the fat, and safety and other problems associated with the presence of large quantities of hot oil.
There have been many attempts to reduce the fat content of potato chips, while retaining product features required for consumer acceptance, such as crispness, a pleasing mouth feel, an acceptable taste, a wrinkled texture, and a light brown appearance after cooking. In one approach, non-fatty liquids such as silicones may be substituted for the cooking fat. In another approach, only a portion of the cooking operation is carried out in a deep fat fryer, with the remaining portion being accomplished in an air-circulating oven or a microwave oven. Various other types of heaters such as radiant heaters have also been tried.
As indicated, there have been attempts to utilize microwave heating in the preparation of potato chips. Microwave heating has been used in conjunction with deep fat frying. However, it has been reported that reducing the water content of a potato slice with a microwave by more than a few per cent prior to deep fat frying causes an unduly hard and dry potato chip because of excessive starch gelatinization. According to U.S. Pat. No. 4,283,425 to Yuan, et al., preparation of a chip from a slice of potato having acceptable characteristics has been accomplished entirely by microwave heating, but only when the potato slice is first coated with a globular protein before microwave cooking. Yuan. et al., teaches that preferably, a second layer, of edible fat or oil should be coated on the potato slice over the globular protein coating. Prior to the invention, the protein coating was thought to be essential in the preparation of a potato chip by this process, and it was believed that the globular protein forms a translucent film on the surface of the potato chip to give the proper appearance, texture and color.
While the latter approach of Yuan, et al., results in greatly reduced fat content, particularly when a layer of edible fat or oil is not applied, this process still requires coating the potato slice with a globular protein. In the preferred embodiment of the Yuan. et al. approach, after the potato slice is coated with the globular protein, the chip is then coated with oil by dipping or spraying, and is then cooked in a microwave oven.
Thus, there exists a continuing need for an improved potato chip having no added fat or globular protein coating. Such a chip would desirably be prepared from potatoes without the need for any precooking coatings, particular globular protein coatings or any oils or fats, but which would be compatible with the use of non-globular protein additives such as surface coatings of salt, non-globular protein flavorants, spices or other ingredients. The flavor, texture, appearance and other features of the potato chip must be acceptable to the consumer, and should be at least as goods as for existing potato chips. The process for preparing the potato chip must also be sufficiently economical to be commercially practical. The present invention fulfills this need, and further provides related advantages.